Elevator



Aug. 4, 1931. A, T M'UNNS- 1,817,418

ELEVATOR Filed Feb. 18, 1929 4 Sheets-Sheet l m 3335" .in

IAllg. 4, 1931. A, T MUNNS 1,817,418

ELEVATOR Filed Feb. 18. 1929 l4, Smets-sheet 2.

Aug. 4, 1931'. A. T. MUNNs 1,817,418

' ELEVATOR Filed Feb. 18, 1929 4 sheets-Sheet 4 Patented Aug. 4, 1931 y UNITED STATES PATENT OFFICE ABTHUB. '1'. IUNNSOII' SANTA IUNICA. CAIJI'OBJIIA y navman Application tiled lebrnry 18, 1929. lerial No. 340,901.

My invention relates to elevators of lthe type embodying a platform supported on a lazy-tong structure, the latter being operable by a mechanism to raise and lower the platform and to support the platform at an desired elevation within the range of a justment of the lazy-tong.

The mechanisms heretofore pro osed for moving the lazy-ton s to extende position from a folded osition have been such as to render very iflicult the initial actuation thereof to the extent of requiring a relatively greater source of power and one wholly beyond the range of practicability articularly where the elevator is a orta le one and great loads are adapted to e lifted.

It is a purpose of my invention to provide in an elevator of the type above described, a mechanism .for operating the lazy-tong structure which is characterized by exerting a force vertically upward and-in such manner that the structure may be moved to an extended position with the application of a minimum amount of force and even when elevating relatively heavy loads. My operating` mechanism is `characterized further by the application to the levers of the lazytong structure of forces which act horizontally to contract the ends of adjacent levers to the end of moving the structure to an extended position beyond that possible by the vertical force or forces exerted by the operating mechanism.

I will describe only one form of elevator a embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings:

Fig. 1 is a view showing in side elevation one form of elevator embodying my invention in applied position to. av` motor truck.

Figs. 2 and 3 are enlarged vertical sectional views taken on the lines 2-2 and 3-3, respectivelyof Fig. 1. y

Fig. 4 is a fragmentary vertical sectional view taken on the line 4-4 of Fig. 1.

ig. 5 is a vertical longitudinal sectional view taken on' the line 5`5 lof Fig. 3.

Fig. 6 is a semi-diagrammatic view of the elevator as shown in the preceding viewsv ventional form in order that the elevator o0 which it supports may be readily moved from place to place and hence rendered portable. The elevator.l may be directly applied to the chassis of the truck but in the pres- 'ent instance I have shown the elevator sup- 65 ported on a supplemental frame 16 which is' fixed to and supported on the chassis 15 of the truck. The sup orting frame 16 isfof rectangular form an is of such length that its rear end projects beyond the corresponding end of t ie chassis in order that it may accommodate and support a lazy-tong structure having relatively long levers that it may be extended vertically to relatively 'high elevations. The lazy-tong structure in the pres- 7.7i ent instance comprises alower unit and an upper unit, designated respectively at L and L1, and each consisting of two pairs of levers 17 and 17a respectively, disposedl at opposite sides of the supporting frame 16 and vtw the levers of each air arranged in intersecting relation and ulcrumed at the point of intersection so as to be free to be moved to folded or extended position. As illustrated to advantage in Fi 4, stub axles 18 provide 85 the fulciunis-for t e levers 17 of the lower lazy-tong unit, while stub axles 19 provide the fulcrum points for the levers 17a ofthe upper unit L1. One lever of each pair of levers of the lower unit L are pivoted on a 00 shaft 20 and journaled in the frame 16, and which shaft is adapted to be operated manually or by power for actuating the mechanism to operate the lazy-tong structure. The lower ends of the remaining levers of the |16 lower unit are connected to each other by an axle 21, and this axle is movable within yokes 22 secured to the upxper side of the supporting frame 16. By t is construction the levers connected by the axle 21 are free to 10 move vlongitudinally within Athe yokes 22, thus-permitting the lower unit L to be moved to extended and folded positions.

The upper'unit L1 is of course supported on the lower unit and for this purpose axles 23 are provided which extend through the meeting ends of the levers of the two units to provide a pivotal. connection between the same as illustrated to advantage in Fig. 3. The upper end of one lever 1701 of each pair is fixedly secured to the under side of a platform P by means of an`axle 24 mounted in brackets 25 secured to the platform. The upper ends of the other two levers are connected by an axle 26, and this axle is provided with a pulley 27(Fig. 3) which is movable ir a yoke 28 secured to they under side of the platform P. This structure permits movement of the axle 26 longitudinally within the yoke 28 so that the corresponding ends ofthe levers are free to move within the yoke in allowing the upper unit to occupy folded and extended positions.

For operating the aforo/described lazytong structure so that it may be moved to anextended position on the truck forelevating the platform P and similarlyto move the lazy-tong structure to a folded position in a manner to control the descent of 'the platform, I provide a mechanism which comprises a series of pulleys for cables, and which therefore may be termed a exible mechanism. This mechanism includes the shaft 20 to which is fixed a pair of windlasses 29 about which latter are wound a pair of cables 30 as clearly illustrated in Fig. 2. From the windlasses, the cables 3Q are extended rearwardly and then upwardly and around pulleys 31 (Fig. 5), mounted on the axle 21. From the pulleys 31 the cables are extended forwardly and over pulleys 32 mounted on the stub axle 18. From this point they are extended forwardly and about pulleys 33 mounted on one of the axles 23, and from the latter rearwardly and about pulleys 34 on the other axle 23. From the pulleys 34 the cables are again extended forwardly and about pulleys 35 mounted on the axle 24, and from the latter pulleys the cables are extended rearwardly where their ends are fixed to the axle 26.

This cable and pulley mechanism is adapted to be operated by rotation of the shaft 20 to wind the cables 30 thereupon and to thereby shorten the cables in transmitting horizontal forces to the ends of the levers 17 and 17a whereby the ends of such levers motor of the truck. To prevent un'windin'g of the cables from 4the wmdlasses, thel shaft 20 is provided with a ratchet wheel 37 engaged by a pawl 38 that may be moved manuall to a released position for freeing the sha t and thus releasing the cables to allow the lazy-tong structure to descend to fronted position. f

As previously expressed herein, initiating movement of the lazy-tong structure to extended position is very difficult particularly when dealing with relatively Aheavy loads, and although the pulley and cable mechanism thus far described is sufficient to move the lazy-tong structure when dealing with light loads, it is incapable of initiating movement of the lazy-tong structure when elevating relativelyheavy loads. However, such mechanism may be rendered operable to extend the lazy-tong structure when dealing with heavy loads by the provision of one or more arms 39 fixed to and depending from the levers 17a of the upper unit at points above the fulcrum 19. In the present instance I have shown each of the levers 17a provided with a single arm on the lower end of which is mounted grooved pulley 40 to receive a cable 30 in the manner illustrated in Fig. 5. As here shown the lazytong structure is in completely folded position, the arms 39 extending below the supporting frame 16 and thc pulleys 40 engaging those stretches of the cables 30 which extend between the pulleys 31 and 32 anfl 32 and 33, all in such manner that the cabh` stretches are extended in a V form.

In practice, the mechanism for moving the lazy-tong structure to extended position is operated by rotating the shaft 20 to wind the cables on the windlasses. When initiating such movement the cables under the pulling force exerted by the windlasses tends to remove or `straighten the V-shapcd stretches of cable and in consequence of which the pulling force which may be said to be acting horizontally is, by reason of thel arms 39, converted into a .vertical force which operates to move the arms upward.4 As the arms are fixed to the levers 17a ad- ]acent to their upper ends, it will be clear that the vertical force or forces acting through the arms will operate to movethe levers 17a upward to extended position. The lifting action of the cables in respect to the arms will be understood from a. comparlson of Figs. 5 and 6 from which it will be seen that initially the cables exert a force vertically through the arms 39 to first move the levers of the upper unit to extended position and all before the cables exert any force upon the levers of the lower unit. This application of force vertically continues until the V-shaped stretches of cables have been transformed into asingle linear stretch as illustrated in Fig. 6 when this lfli lll

lll

part of the cables is no longer effective through the arms 39 to extend the levers. However, with continued operation of the windlasses the cables acting through the pulleys about which they are trained exert resultant forces which act substantially horizontal to draw the lever' ends toward each other until the lazy-tong. structure is moved to fully extended position. In this manner the platform P is moved to the elevated position shown in Fig. 7, and it will be understood that the lazy-tong structure may be retained extended and the platform elevated by securing the shaft 20 against reverse rotation by means of the pawl and ratchet. e l

4The platform P is shown in Figs. 5 and 7 as provided with a supplemental section P1 which is hingedly mounted thereon to occupy folded and extended positions. lThe operators seat on the motor truck is shown rovided with a protecting top or housing Il which in its association with respect to the platform section P1 functions as a proljection 'to move the section to the-folded posito form an extension of the latter.

tion shown in Fig. 5. The hinged mounting of the platform section is such that once it is elevated clear of the top H it gravitatcs to the position shown in Fig. 7 in which it is aligned horizontally with the platform P As vthe elevator is lowered to folded position, the platform section P1 engages the housing H and is thus moved to the folded position shown in Fig. 5. 1

In the-present instance I have shown the platform P and its supplemental section provided at intervals with vuprights or posts 41 connected by chains 42 to form a pro: tecting railing around the" platform. The

v chains allow the section P1 to be moved to folded and extended positions on the main platform, and with the section extended the chains and posts form a continuous railing around the platform,

Although I have herein shown and described only one form. of elevator embody'- ing my invention, it is t0 be understood that various changes and-modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims. I claimz' 1. `In an elevator, a lazytong structure, flexible means for moving said structure ver-l ticallyto extended position, and means on the uppermost levers of said structure and between the ends of said levers by which the fiexible means when operated exerts a force vertically u ward on said leverswhereby movements o said -structure to extended position is initiatedl by upward movement of said levers.

2. ln an elevator, a lazy-tong structure, iexiblemcans for moving said structure vertically to extended position, said means inlevers whereby movement o said structure to extended position isl initiated by upward movement o said levers. v

3. In an elevator, a truck havin a seat top, a lazy-tong structure mounte on'the truck for movement vertically to occupy extended and folded positions, means for operating said structure, and a platform on said structure having a parthinged to occupy folded position and to lgravitate to extended position, said part being positioned to be engaged by said seat top and moved to folded position.

4. In an elevator, a lazy-tong structure, pulleys at the ends of the levers of said structure, cables trained about the pulleys so that when operated they will exert forces to draw the ends of the levers toward each other for moving the structure to extended position, arms fixed to and depending from the uppermost levers of said structure, pulleys on the arms, about which the cables are trained, said pulleys and arms being positioned to produce in the cables V-shaped stretches that tend to straighten when the cables are actuated to move the arms vertically upward, a'nd means for operating the cables. n

5. In an elevator, a lazy-tong structure, pulleys at the ends of the levers of said structure, cables trained about the pulleysv so that when operated they will exert forces to draw the ends of the levers toward each other for moving the structure to extended position, arms fixed to and depending from the uppermost levers of said structure, pulyleys on the arms and pulleys on the fulcrums of the lowermost levers of said structurev about which the cables are trained, said pulleys and arms being positioned to duce in the cables V-sha ed strips w ich tend to straightenwhen t e cables are actuated to move the arms vertically upward, and means for operating the cables.

ARTHUR T. M UNNS.`

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